Link information management method

ABSTRACT

A link information management method which is capable of reducing the number of steps of a link maintenance processing of link information indicating a corresponding relationship between geographical information in a geographical information system and attribute information. To realize the method, geographical information are compared and judged by translating first geographical information based on corresponding points judged as the same points inputted on first and second geographical information by an operator. Further, update days of link information and attribute information are compared and judged, and current link information which causes the second geographical information and the attribute information to be correlated with each other is generated based on the compared and judged results of the link information and the attribute information. Then, attribute information and a closed area on the second geographical information are displayed by using the current link information thus generated.

[0001] CROSS-REFERENCE TO RELATED APPLICATION

[0002] This is a Continuation-in-part Application of U.S. Ser. No.08/405,987 filed on Mar. 17, 1995 and assigned to the present assignee.The disclosure of that application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0003] The present invention relates to a link information managementmethod for use with an apparatus or a system (e.g. geographicalinformation system) which handles area information (geographicalinformation, document, drawings, etc.) and attribute information(information stored in database or file, etc.).

[0004] Geographical information systems have hitherto been known as asystem for supporting data retrieval/reference by using a correspondingrelationship between geographical information and attribute information.The geographical information system has a fundamental function toretrieve attribute information such as geographical information andresidents information from each other. For example, the geographicalinformation system is able to display residents information bydesignating a house on a map. Conversely, the geographical informationsystem is able to display a house of a corresponding resident on a mapby designating a name of resident in residents information. As thegeographical system having the above-mentioned functions, there hashitherto been known a self-governing body geographical system “ARISTOWN”(PIXEL, No. 56, pp. 73-78) having a function to make use of maps andattribute information such as road information and land information inassociation with each other.

[0005] To realize the fundamental function of the geographicalinformation system, a correspondence relationship (hereinafter referredto as “link information”) between geographical information and attributeinformation should be saved in any forms. Therefore, when the operationof the geographical information system is started, a registration workfor registering link information is indispensable for the operation ofthe geographical information system. Further, during the geographicalinformation system is operated, a maintenance for each of geographicalinformation, attribute information and link information becomesnecessary. In a link information registration processing or a linkinformation maintenance processing, since link information is registeredand changed while a corresponding relationship between geographicalinformation and attribute information is constantly maintained, the linkinformation registration on processing and the link informationmaintenance processing become cumbersome as compared with the case wheregeographical information and attribute information are each registeredand changed. Moreover, as the scale and the kind of geographicalinformation and attribute information to be handed increase, the recordnumber of registered link information increases in a combinatorialmathematics fashion. For the above-mentioned reason, there are requiredmany steps of link information registration and maintenance work. Tosolve this problem, there has been considered a support technology inorder to decrease the number of steps of the link informationregistration and maintenance work.

[0006] For example, as a support technology for supporting a linkinformation registration, U.S. Pat. No. 5,625,771 describes a charactercursor function. According to the character cursor function, whengeographical information and attribute information are associated witheach other, an amount of an operator eye movement of on a display screencan be decreased and an efficiency of a link information registrationprocessing can be increased by displaying a part of attributeinformation near a mouse cursor.

[0007] Also, as a technology for supporting a link informationmaintenance, there is a technology (JP-A-7-73297) for automaticallymaintaining names of residents on maps by using link information betweenresidents information and geographical information. According to thistechnology, when a resident of a certain house is changed from the statethat geographical information and residents information with respect tothe above-mentioned house are linked, for example, a written name of aresident contained in geographical information to which changed residentinformation should be linked can be changed automatically.

[0008] Further, as another technology for supporting a link informationmaintenance, there has hitherto been known a technology (JP-A-6-28438)for executing a link maintenance between an old map and a new map bycorrecting position information of link information corresponding to aclosed area on the old map. According to the above-mentioned technology,when link information of the old map and the new map in which positioninformation is slightly changed with respect to the old map is corrected(e.g. a map of 1996 edition is changed to a map of 1997 edition),position information which was included in link information of the oldmap is corrected and then copied to the new map.

[0009] As described above, when the geographical information system isoperated, there is examined a technology for supporting an access andmaintenance of link information.

[0010] On the other hand, the above-mentioned conventional technologiesare not satisfactory in supporting the access and maintenance of linkinformation. For example, the above-mentioned character cursor functionis unable to support the case where there exists link information thathas already been registered. That is, when geographical information isupdated under the situation that link information has been alreadyregistered on geographical-information, the character cursor function isable to only display attribute information obtained before the linkinformation is registered near a cursor. Therefore, link informationwith respect to current geographical information has to be re-registeredone more time from the beginning. That is, the link information that hasalready been registered cannot be used effectively.

[0011] JP-A-7-73297 describes a technology for updating geographicalinformation and residents information when there already existed linkinformation. However, this technology has no support function to supportthe case where residents information is registered additionally afterthe link information has been registered. Considering this technologyfrom a system operation standpoint, when new residents information isadditionally registered after link information has been registered, itis frequently observed that there occurs residents information which isnot corresponding to geographical information (i.e. there exists no linkinformation). However, according to the method described inJP-A-7-73297, the residents information that is additionally registeredafter the link information has been registered is missed, and hence theresidents information that was additionally registered cannot besupported by the link maintenance processing.

[0012] Also, JP-A-6-28438 is unable to maintain link information when ascale or a direction is different between old and current geographicalinformation. On the other hand, considering this technology from asystem operation standpoint, a class of geographical information that ismade corresponding to attribute information also should be changed asbusiness contents handled by the geographical information system arechanged. Also, since a business becomes complicated, detailedgeographical information become necessary so that a map of scale,1-50,000 should be changed to a map of scale, 25,000. However, accordingto the method described in JP-A-5-28438, link information is maintainedin a manner in which position information of link information registeredon the old map is succeeded substantially as it is. Therefore, whenscales or directions of old geographical information and currentgeographical information are considerably different from each other,link information registered on the old geographical information cannotbe correctly changed to link information of current geographicalinformation.

[0013] Incidentally, JP-A-9-282330 describes a system for supporting aconstruction of database by associating database and document as asystem similar to the geographical information system. Also in thesystem described in JP-A-9-282330, link information by which databaseand document are associated with each other should be registered andmaintained similarly to the geographical information system. As aresult, there arises a problem similar to the above-mentioned problemfrom a standpoint of the number of steps in the link informationregistration and maintenance processing similarly to the geographicalinformation system.

SUMMARY OF THE INVENTION

[0014] It is an object of the present invention to solve theabove-mentioned problems encountered with the conventional technologiesand to reduce the number of steps in a link maintenance processing in ageographical information system or the like.

[0015] In order to attain the above objects of the present invention,according to a first aspect of the invention, there is provided a linkinformation management method using a computer system including a CPU,an input device, a display device and having a storage device storingfirst area information concerning a first area including a closed area,second area information concerning a second area including a closedarea, attribute information correlated with said first area informationand old link information indicative of a corresponding relationshipbetween said first area information and said attribute information. Saidlink information management method comprises the steps of:

[0016] a) displaying the first area and the second area in accordancewith the first area information and the second area information,respectively, and obtaining position information of corresponding pointsof a predetermined number indicative of the same positions instructed onthe first area and the second area through said input device;

[0017] b) obtaining a translation equation for translating the firstarea information into the second area information by using the positioninformation of corresponding points and judging similarity between theclosed area of the first area information and the closed area of thesecond area information translated based on the translation equation;

[0018] c) generating current link information which causes the secondarea information and the attribute information to be correlated witheach other based on the judged results of the similarity and the oldlink information; and

[0019] d) displaying the attribute information and the closed area onthe second area on the display device by using the current linkinformation thus generated.

[0020] When the aspect of the invention is applied to a geographicalinformation system, for example, the first area information is oldgeographical information (geographical information in which linkinformation has been already registered), and the second areainformation is current geographical information (geographicalinformation in which link information has not yet been registered). Whena similarity of closed area is judged, a coordinate transformationprocessing is executed between the old geographical information and thecurrent geographical information based on the corresponding pointsdesignated by an operator, and a similarity is judged by comparingclosed areas included in the old geographical information and thecurrent geographical information transformed on the basis of thecoordinate transform processing. Incidentally, of attribute information,newly-registered attribute information (information having no linkinformation) may be displayed on the display device.

[0021] According to a second aspect of the invention, in the firstaspect, the old link information and the attribute information arecompared and grouped by using registration/update day in the step c) andthe current link information is generated based on compared and groupedresults obtained by the registration/update day, judged results of thesimilarity and the old link information in the step d).

[0022] According to a third aspect of the invention, in the first orsecond aspect, current link information is generated so as to have aclass indicative of whether or not generated current link information iscertain current link information in the step c), attribute informationlinked by the current link information and the closed area on the secondarea are displayed in a first mode or a second mode in response towhether or not generated current link information is certain currentlink information, and a class indicating whether or not correspondingcurrent link information is certain current link information is changedby operating the displayed attribute information and closed area on thesecond area in a predetermined manner in the step d).

[0023] According to a fourth aspect of the invention, in the first orsecond aspect, a similarity is judged by using character recognizedresults obtained within closed areas of the closed area of the firstarea information and the closed area of the second area information inthe step b), and current link information is generated by using thecharacter recognized results in the step c).

[0024] According to a fifth aspect of the invention, in the first orsecond aspect, a data format of the first area information and a dataformat of the second area information are different from each other. Forexample, even when old geographical information is of the vector formatand current geographical information is of the image format, linkinformation can be changed based on respective position information.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a general flowchart of the present invention;

[0026]FIG. 2 is a block diagram showing a computer system which carriesout the present invention;

[0027]FIG. 3A is a diagram showing residents information;

[0028]FIG. 3B is a diagram showing area information;

[0029]FIG. 3C is a diagram showing link information;

[0030]FIG. 4 is a diagram showing a link information grouped table; and

[0031]FIG. 5 is a diagram showing an example of a picture displayed on ascreen of a display device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0032] An embodiment of the present invention will hereinafter bedescribed with reference to the drawings. A link information managementmethod in a system which manages geographical information and residentsinformation in association with each other will be describedhereinafter. Incidentally, geographical information is informationindicative of geographical features, such as roads and buildings, andcontains closed area information, such as a building displayed as aclosed area.

[0033]FIG. 1 of the accompanying drawings shows a processing outlineaccording to this embodiment by a flowchart. Initially, storedinformation used in this embodiment will be described.

[0034] In area information 1020, there are stored two kinds ofgeographical information called old geographical information 1021 andcurrent geographical information 1022. The old geographical information1021 is geographical information in which a corresponding relationshipbetween a closed area on geographical information and residentsinformation 1030 exists previously as link information 1010. On theother hand, current geographical information 1022 is geographicalinformation in which the link information 1010 indicative of acorresponding relationship between a closed area on geographicalinformation and residents information does not exist before theprocessing which will be described below. Incidentally, as a format forstoring geographical information, there are known formats such as avector format (format for storing area information by using an algebracurve) and an image format (format for expressing area information by anarray of pixels). The format for storing geographical informationaccording to this embodiment may be any of the vector format, the imageformat and other formats as long as the position of the closed area canbe determined. In particular, since the closed area can be extractedfrom an image processing technology which will be described later on,the geographical information of the image format may be handled insubstantially the same manner as the geographical information of thevector format is handled according to this embodiment. That is, in thisembodiment, it is permitted that the formats for storing the oldgeographical information 1021 and the current geographical information1022 may be different from each other. FIG. 3B shows an example of theold geographical information 1021 and the current geographicalinformation 1022 stored as the area information 1020.

[0035] In the residents information 1030 shown in FIG. 1, there isstored residents personal information, such as names and address ofresidents. FIG. 3A shows an example of an arrangement of residentsinformation 1030. The residents information 1030 shown in FIG. 3Aincludes a residents ID 1031, a name 1032 and an update day 1033. In theresidents ID 1031, there is stored a unique key which is used touniquely identify the record of the residents information 1030. In theupdate day 1033, there is stored an update day of each record ofresidents information.

[0036] The link information 1010 shown in FIG. 1 is information forholding a corresponding relationship between the residents information1030 and the area information 1020. As shown in FIG. 1, the linkinformation 1010 includes old link information 1011 and current linkinformation. The current link information is grouped by the followingprocessing to provide certain link information 1012, uncertain linkinformation 1013 and failure link information 1014. FIG. 3C shows anexample of an arrangement of link information. As shown in FIG. 3C,although these four link information are stored as different tablefiles, their data structures as the link information are the same.

[0037] As shown in FIG. 3C, the link information 1010 includes an ID4010, an inner point 4020, a closed area 4030, a residents ID 4040 andan update day 4050. In the ID 4010, there is stored a unique key whichis used to uniquely identify each record of link information. In theclosed area 4030, there is stored information which is used to specify apolygonal area on the map. In the inner point 4020, there is stored apoint (representing point) included in the closed area 4030 as the innerpoint. For example, position information (X00, X01, X02, X03) ofvertexes composing the closed area on the old geographical information1021 of FIG. 3B are stored in a closed area 4030 of the old linkinformation 1011, and the point X0 within this closed area is stored inthe inner point 4020 of the old link information 1011. In the residentsID 4040, there are stored residents ID of residents co-responding to theclosed area described in the closed area 4030 of a residents ID 1031 ofthe residents information 1030. By such link information 1010, theclosed area on the geographical information (area information 1020) ismade corresponding to the residents information 1030. Incidentally, inthe following description, of the closed areas on the geographicalinformation 1020, a closed area which is made corresponding to theresidents information 1030 by the link information 1010 is referred toas an anchor area. In an update day 4050 of the link information 1010,there is stored update day of each record.

[0038] In FIG. 1, position information 1040 is information which isinputted when an operator designates a position on old geographicalinformation or current geographical information displayed on a screen ofa display device by operating an input device, such as a keyboard 2020or a mouse 2030 shown in FIG. 2.

[0039] Before describing each Processing shown in FIG. 1, a systemarrangement and an example of a picture according to this embodimentwill be described below.

[0040]FIG. 2 is a block diagram showing a computer system which carriesout this embodiment. The system according to this embodiment includes adisplay device 2010, a keyboard 2020, a mouse 2030, a computer apparatus2040 and a storage device 2050. The computer apparatus 2040 includes aCPU (central processing unit) 2041 and a memory 2042. Each processingshown in FIG. 1 is executed by using the system apparatus shown in FIG.2. In the storage device 2050, there are stored the residentsinformation 1030, the link information 1010 and the area information1020 shown in FIG. 1. Incidentally, if the memory 2024 has asufficiently large storage capacity, then the residents information1030, the link information 1010 and the area information 1020 may all bestored in the memory 2042. Also, a program for executing each processingshown in FIG. 1 is stored not only in the memory 2042 but also may bestored in a medium such as floppy disks. A suitable storage device suchas a CD-ROM, DVD-ROM and MO may be used as the storage device 2050, andthe area information 1020 represented by geographical information may bestored in such a storage device.

[0041]FIG. 5 shows an example of a picture displayed on the displaydevice 2010 according to this embodiment. An operation procedureaccording to this embodiment will hereinafter be described withreference to FIG. 5.

[0042] The old geographical information 1021 of FIG. 3B is displayed onan old geographical information display screen 5020 shown in FIG. 5. Thecurrent geographical information 1022 of FIG. 3B is displayed on acurrent geographical information display screen 5020 of FIG. 5. Anoperator selects “LINK POINT DESIGNATE” 5021 of the menu shown in FIG.5, and designates three points (e.g. P, Q, R) on the display screen 5010of the old geographical information 1021. Then, the operator designatesthree points which are judged as “THE SAME POINTS AS THOSE DESIGNATEDPOINTS ON THE OLD GEOGRPHICAL INFORMATION 1021” on the display screen5020 of the current geographical information 1022. FIG. 5 shows the casein which the operator designated points S, T, U as points correspondingto the points P, Q, R.

[0043] Incidentally, although FIG. 5 displays maps in different scalesin the display screen 5010 of the old geographical information and thedisplay screen 5020 of the current geographical information, in thesystem according to this embodiment, the old geographical informationdisplay screen 5010 and the current geographical information displayscreen 5020 may be displayed in an enlarged or reduced scale,respectively. When the corresponding points are designated by using thisfunction, if both maps are displayed on the screens in such a mannerthat the scales become coincident with each other on both displayscreens by properly changing the reduction ratios of both maps, then acorresponding relationship between the both maps becomes easy tounderstand. Also, in this embodiment, although the display screens 5010and 5020 which display the whole of the area information 1020 for thesake of convenience, the whole of the area information 1020 need not bedisplayed on the screen. The area information 1020 may be displayed inthe format in which the corresponding points can be inputted such aswhen the area information 1020 is displayed partly. Furthermore, the oldgeographical information 1021 and the current geographical information1022 may be displayed on the display area of the same window in anoverlapping fashion. Incidentally, in this embodiment, even when thecorresponding points are inputted to the partial area of geographicalinformation, link information outside the display screen may be changedby other link information by a processing which will be described lateron.

[0044] Then, when the operator selects “LINK CHANGE” 5022 on the menu,the processings 1001 to 1008 shown in FIG. 1 are executed. The systemgenerates certain link information 1012, uncertain link information 1013and failure link information 1014 shown in FIG. 3C from the old linkinformation 1011 shown in FIG. 3C. Then, anchor areas on the currentgeographical information 1022 are displayed by colors such as blue oryellow in response to the classes of the link information thusgenerated. The certain link information is link information in which alink between residents information and geographical information is madecertain; the uncertain link information is link information in which alink between residents information and geographical information will bemade certain probably although is not judged to be certain; and thefailure link information is link information in which residentsinformation that could not be linked to geographical information arestored. When the operator selects an anchor area (closed area which ismade corresponding to the residents information 1030) on the currentgeographical information 1022 by using the mouse 2030, the content ofthe residents information 1030 corresponding to that anchor area isdisplayed on the residents information display screen 5030.

[0045] On the other Land, a list of the residents information 1030corresponding to the uncertain link information 1013 and the failurelink information 1012 is displayed on “UNCERTAIN/FAILURE RESIDENTSINFORMATION DISPLAY SCREEN” 5040. In this list, residents names whichare made corresponding by the uncertain link information 1013 aredisplayed in the form such that they can be distinguished from residentsnames which are made corresponding by the failure link information 1014.In the example of FIG. 5, “

(OSAKA HANAKO in Roman expression)” displayed in italic characters isresidents name which is made corresponding by the uncertain linkinformation 1013. Remaining “

(KANSAI ICHIRO)” and “

(TANAKA JIRO)” are residents names which are made corresponding by thefailure link information 1012. Incidentally, instead of displayingresidents names by different fonts, residents names may be distinguishedby different colors.

[0046] The processing in this embodiment will hereinafter be describedwith reference to FIG. 1 and the display examples of FIG. 5. Theprocessing according to this embodiment includes a calculate coordinatetranslation matrix 1001, a translate inner point 1002, an extract areafrom geographic information 1003, a compare similarity level of areashape 1004, a compare update day 1005, a group link information 1006, adisplay anchor area 1007, and a display residents information 1008.

[0047] In the calculate coordinate translation matrix 1001, on the basisof the position information of point sequences (P, Q, R) and (S, T, U)which are designated on the screen of FIG. 5 by the operator, atwo-dimensional matrix M and a two-dimensional vector (longitudinalmatrix) V which satisfy the following equation. The following componentsp, q, r, s, t and u are expressed by two-dimensional vectors(longitudinal matrix) which have position information of point sequences(P, Q, R) and (S, T, U) as components as:

[0048] M·p+V=s, M·q+V=t, M·r+V=u

[0049] According to a solution of simultaneous equations, theabove-mentioned M, V can be obtained from the position information ofthe corresponding three points (P, Q, R) and (S, T, U). Incidentally,assuming several premises between geographical information, then thenumber of the designated points on the display screen can be reduced toone or two points. For example, if magnifying powers of lengths andbreadths in the old geographical information 1021 and the currentgeographical information 1022 are equal to each other, respectively,then M is given as a rotation matrix multiplied by a constant. Thus, M,V can be calculated by designating only two points on the displayscreens 5010 and 5020. Also, if the magnifying powers of lengths andbreadths in the old geographical information 1021 and the currentgeographical information 1022 are equal to each other, respectively, andthe directions thereof also are equal to each other, then M is given asa unit matrix. Thus, M, V can be calculated by designating only onepoint each on the display screens 5010 and 5020. While the three pointsare designated on the respective geographical information as describedabove, if the above-mentioned hypothesis is established, then the numberof the designated points may be either one point or two points.Moreover, in order to reduce an error in the coordinate translation, itis possible to increase an accuracy of the calculate coordinatetranslation matrix 1001 by designating four points or more.

[0050] In the translate inner point 1002, the coordinate translation iseffected on each inner point 4020 of the old link information 1011 byusing the M and V obtained at the calculate coordinate translationmatrix 1001, thereby obtaining points on the current geographicalinformation 1022. FIG. 3B shows the state in which a translated innerpoint Zi=M·Xi+V (i=0, 1, 2) has been obtained as a point on the currentgeographical information 1022 after the coordinate translation has beeneffected on each inner point Xi (i=0, 1, 2) of the old geographicalinformation 1021.

[0051] The extract area from geographical information 1003 extracts theclosed area of the current geographical information 1022 by using thetranslated inner point Zi obtained in the translate inner point 1002 andthe current geographical information 1022. If geographical informationis stored in the vector format, then the closed area is stored in thegeographical information of the vector format itself so that the closedarea including the translated inner point can be extracted by judging“whether or not each closed area includes the translated inner point”.If on the other hand geographical information is stored in the imageformat, then a closed area can be extracted by using an image processingtechnology. As the image processing technology, “ALGORITHM FOREXTRACTING A CLOSED AREA INCLUDING SPECIFIC POINT” for extracting acontour line constructing an area by tracing black point sequences on animage is disclosed by “IMAGE PROCESSING AND PATTERN MEASURINGTECHNOLOGY” edited by THE JAPAN SOCIETY OF MECHANICAL ENGINEERS (pp.82-83, published by Asakura Shoten, 1986). By using the above-mentionedalgorithm, it is possible to obtain a closed area including a specificpoint (inner point in this embodiment) from the geographical informationof the image format. That is, regardless of whether the geographicalinformation is stored in the vector format or the image format, therecan be obtained the closed area including the inner point Zi. FIG. 3Bshows the case in which a closed area (Z00, Z01, Z02, Z03) has beenobtained as the closed area including the inner point Z0 in the currentgeographical information 22.

[0052] To simplify the description and the drawings, let us describe thepresent invention on the assumption that a closed area (Zi0, Zi1, Zi2,Zi3) is obtained with respect to the inner point Zi (i=0, 1) of eachtranslation. However, FIG. 3B shows the case that a corresponding closedarea does not exist with respect to the translated inner point Z2 in thecurrent geographical information 1022. Incidentally, the followingdescription of this embodiment can be similarly applied to a closed areawhich is generally shaped as a polygon.

[0053] The compare similarity level of area shape 1004 compares asimilarity between “the closed area of the current geographicalinformation 1022 obtained in the extract area from geographicalinformation 1003” and “the closed area 4030 of the old link information1011” based on the translated coordinates (M, V) obtained in thecalculate coordinate translation matrix 1001. Initially, a closed areatranslated into the coordinate system of the current geographicalinformation 1022 is calculated by effecting the coordinate translationprocessing (coordinate translation by M, V) on the “closed area 4030 ofthe old link information 1011”. In the following description, the closedarea which results from effecting the coordinate translation on theclosed area 4030 (Xi0, Xi1, Xi2, Xi3) of the old link information 1011will be described as (Yi0, Yi1, Yi2, Yi3). Here, Yij=M·Xij+V isestablished. The thus obtained closed area (Yi0, Yi1, Yi2, Yi3) of thesame coordinate system and the closed area (Zi0, Zi1, Zi2, Zi3) obtainedby the extract area from geographical information 1003 are compared insimilarity level of area shape. The similarity level of area shape iscompared by using a DP (Dynamic Programming) matching which iswell-known in speech recognition and image recognition. The DP matchingis an algorithm in which audio information or image information isconverted into a frequency component by a mathematical method, a conceptof distance is defined between frequency components and a similarity ofaudio information or image information is judged based on a magnitude ofdistance. Detailed contents of the DP matching is described in “PATTERNUNDERSTANDING” edited by Yoshiaki Shirai (pp. 202-211, published byOHMSHA LTD., 1987). In this embodiment, a distance obtained by the DPmatching is assumed to be L, and a proper interval (a, b) (a>0) isassumed to be on a straight line. Then, a similarity of level betweenthe closed areas is judged as follows. In this case, the distance L is aminimum value of sum total of distances between point sequencescorresponding to various routes ranging from a starting point (a1, b1)to an ending point (al, bJ) when a point sequence (ai, bj) is composedof two data strings {ai} and {bj} which are to be compared in similaritylevel. The smaller the value of L becomes, the more the change of thetwo data strings becomes similar. Accordingly, it is indicated that asimilarity level of the two judged targets is high,

[0054] (1) If the distance L is contained in the interval [0,a]: it isjudged as the same area.

[0055] (2) If the distance L is contained in the interval (a, b): it isjudged as the uncertain area.

[0056] (3) If the distance L is contained in the interval [b, ∝]: it isjudged as the failure area.

[0057] Incidentally, the algorithm used in the compare similarity levelof area shape 1004 is not limited to the DP matching, and may be analgorithm using comparison of area and the number of vertexes of aclosed area. There can be any kinds of algorithms for comparing asimilarity level of closed area.

[0058] A compare update day 1005 compares update days of the old linkinformation 1011 and the residents information 1030. Latest update daystored in the old link information 1011 and the update day 1033 of thecorresponding residents information 1030 are compared and grouped asfollows:

[0059] (1) Residents information≦old link information: this is the casein which residents information is older than the link information or thecase for the same day.

[0060] (2) Residents information>old link information: this is the casein which residents information is newer than link information, and thereis then the large possibility that new residents information will not bereflected on the link information.

[0061] Incidentally, the method of comparing update days is not limitedto the above-mentioned methods.

[0062] A group link information 1006 groups the residents information1030 and the old link information 1011 based on a table of linkinformation group shown in FIG. 4 which is determined by the comparedresult of the compare similarity level of area shape 1004 and comparedresult of the compare update day 1005, and generates the certain linkinformation 1012, the uncertain link information 1013 and the failurelink information 1014. In the certain link information 1012 and theuncertain link information 1013, there are stored the inner point andthe closed area obtained by the extract area from geographicalinformation 1003 together with ID, residents ID and update day. AlthoughID, residents ID and update day are stored in the failure linkinformation 1014, it is frequently observed that the inner point and theclosed area are stored in or not stored in the failure link information1014. When each record of the residents information 1030 is madecorresponding to the old geographic information 1020 by the old linkinformation 1011, the inner point and the closed area obtained by theextract area from geographic information 1003 are stored in the failurelink information 1014 (z2 is stored in the failure link information 1014as the inner point in the example of FIG. 3B). In other cases, nothingis stored in an inner point 4022 and a closed area 4032 of the failurelink information 1014. FIG. 3C shows an example of stored results oflink information according to this processing.

[0063] A display anchor area 1007 displays anchor areas on the currentgeographic information 1022 by using the link information 1010 obtainedin the group link information 1006 in the different forms in response tothe similarity level of area shape. For example, anchor areas of thecurrent link information 1012 and the uncertain link information 1013are displayed in blue and yellow, respectively. FIG. 5 shows an exampleof a displayed picture of the anchor area.

[0064] Display residents information 1008 groups the residentsinformation 1030 by using the link information 1010 obtained in thegroup link information 1006, and displays a grouped result on thedisplay screen. Of the residents information, residents information inwhich the value of the residents ID 1031 is stored as residents ID 4042of the uncertain link information 1013 or the failure link information1014 are displayed on a display screen 5040 of “UNCERTAIN/FAILURERESIDENTS INFORMATION” shown in FIG. 5 in the form of a list.

[0065] Incidentally, the class (“CERTAIN” OR “UNCERTAIN” OR “FAILURE”)of the link information relative to the current geographic information1022 may be changed at the record unit of the link information when theoperator operates the display screen. For example, the operatordouble-clicks a resident name (“

” in FIG. 5) displayed on the display screen 5040 of the“UNCERTAIN/FAILURE RESIDENTS INFORMATION”) by the mouse 2030 of FIG. 2.Then, the system side judges that the operator determines the linkinformation, and moves the corresponding record of the selecteduncertain link information to the record of the certain link information1012. Then, the resident name of the certain residents information isdeleted from the display screen 5040 of the “UNCERTAIN/FAILURE RESIDENTSINFORMATION”. Thus, the uncertain link information can be made certainwith ease.

[0066] Incidentally, while the certain link information 1012, theuncertain link information 1013 and the failure link information 1014are comprised of different tables as shown in FIG. 3C in the embodimentof the present invention, these link information may all be stored inone table and each record may hold a flag indicating that the record is“certain”, “uncertain” or “failure”.

[0067] Further, in the above-mentioned embodiment, while the presentinvention is applied to the geographic information system by way ofexample, the present invention is not limited thereto, and may beapplied to a system which holds link information in which areainformation and attribute information are associated with each other.For example, as a system similar to the geographic information system,there is known a system in which a document and database are associatedwith each other by link information. Since the document has a squarearea (area information) called cell, it is to be understood that theprocessing in FIG. 1 can be similarly applied to the document. That is,the square area on the document is processed in a manner of FIG. 1,whereby a maintenance of link information in which the document and thedatabase are associated with each other can be realized similarly.

[0068] Incidentally, in a document or the like, it is frequentlyobserved that characters such as entry names are described in the cell.Therefore, in the case of the document, a processing of “if characterrecognized results within two square areas agree with each other, thenit is determined that area information become coincident” may be addedto the internal processing of the compare similarity level of area shape1004 of the area information of FIG. 1. If the above-mentionedprocessing is added, then it is possible to increase an accuracyrequired in changing the link information of the link informationmaintenance system in which a document is a target. Also, whengeographic information includes characters in a map, a link informationchange accuracy can be increased by executing the similar processing.

[0069] As described above, according to the present invention, since asimilarity level between two closed areas is judged on the basis ofposition information designated in the old first area information andthe current second area information by the operator, a correspondingrelationship of closed areas on the map can be judged even between areainformation having different scales or directions, thereby making itpossible to change the link information. Therefore, even thepreviously-registered link information can be changed. If current linkinformation is generated considering compared and grouped resultsobtained by the registration or update day, then it is possible togenerate current link information more accurately. If attributeinformation or the like is displayed in the different modes in responseto the class indicating whether the current link information is certainor not and the class can be changed by a predetermined operation, thenuncertain link information, for example, can be made certain with ease,and the link information can be changed with ease. Thus, it becomespossible to support the processing in which link information updatedresults are confirmed by the operator. Further. If newly-registeredattribute information of attribute information is displayed, thenattribute information that the operator should create new linkinformation can be recognized with ease. If the similarity level isjudged by using character recognized results within the closed area andcurrent link information is generated, then the current link informationcan be generated more accurately. Further, even when old and currentarea information are different in data form such as when old areainformation is in the vector format and current area information is inthe image format, link information can be changed. As described above,according to the present invention, it is possible to reduce the numberof steps of a link maintenance processing in the geographic informationsystem.

[0070] Having described a preferred embodiment of the invention withreference to the accompanying drawings, it is to be understood that theinvention is not limited to that precise embodiment and that variouschanges and modifications could be effected therein by one skilled inthe art without departing from the spirit or scope of the invention asdefined in the appended claims.

What is claimed is:
 1. A link information management method using acomputer apparatus including a CPU, an input device, a display deviceand a storage device storing first area information concerning a firstarea including a closed area, second area information concerning asecond area including a closed area, attribute information correlatedwith said first area information and old link information indicative ofa corresponding relationship between said first area information andsaid attribute information, comprising the steps of: a) displaying saidfirst area and said second area in accordance with said first areainformation and said second area information, respectively, andobtaining position information of corresponding points of apredetermined number indicative of the same positions instructed on saidfirst area and said second area through said input device; b) obtaininga translation equation for translating said first area information intosaid second area information by using said position information ofcorresponding points and judging similarity between the closed area ofsaid first area information and the closed area of said second areainformation translated based on said translation equation; c) generatingcurrent link information which causes said second area information andsaid attribute information to be correlated with each other based on thejudged results of similarity and said old link information; and d)displaying said attribute information and the closed area on said secondarea on said display device by using said current link information thusgenerated.
 2. A link information management method as claimed in claim 1, wherein said old link information and said attribute information arecompared and grouped by using access/update day in said step (c) andsaid current link information is generated based on compared and groupedresults obtained by said access/update day, said judged results ofsimilarity and said old link information in said step (d).
 3. A linkinformation management method as claimed in claim 1 , wherein saidcurrent link information is generated so as to have a class indicativeof whether or not the generated current link information is certaincurrent link information in said step (c), attribute information linkedby said current link information and the closed area on the second areaare displayed in a first mode or a second mode in response to whether ornot the generated current link information is certain current linkinformation, and a class indicating whether or not corresponding thecurrent link information is certain current link information is changedby operating the displayed attribute information and closed area on thesecond area in a predetermined manner in said step (d).
 4. A linkinformation management method as claimed in said step (b) in claim 1 ,wherein said similarity is judged by using character recognized resultsobtained within closed areas of the closed area of said first areainformation and the closed area of said second area information.
 5. Alink information management method as claimed in claim 1 , wherein adata format of said first area information and a data format of saidsecond area information are different from each other.
 6. Acomputer-readable storage medium storing a program for implementing alink information management method using a computer system including aCPU, an input device, a display device and a storage device for storingfirst area information concerning a first area including a closed area,second area information concerning a second area including a closedarea, attribute information correlated with said first area informationand old link information indicative of a corresponding relationshipbetween said first area information and said attribute information, saidmethod comprising the steps of: a) displaying said first area and saidsecond area in accordance with said first area information and saidsecond area information, respectively, and obtaining positioninformation of corresponding points of a predetermined number indicativeof the same positions instructed on said first area and said second areathrough said input device; b) obtaining a translation equation fortranslating said first area information into said second areainformation by using said position information of corresponding pointsand judging similarity between the closed area of said first areainformation and the closed area of said second area informationtranslated based on said translation equation; c) generating currentlink information which causes said second area information and saidattribute information to be correlated with each other based on thejudged results of said similarity and said old link information; and d)displaying said attribute information and the closed area on said secondarea on said display device by using said current link information thusgenerated.